Polyolefins and particularly polymonoolefins such as polypropylene are used as bale wrappers, for example, for baling cotton fibers and polyester fibers. In order to recycle the polyolefins such must be adequately cleaned, which includes removing certain contaminants including polyesters and cellulosic materials such as cotton and paper. Sometimes, low levels of such contaminants may be removed during melt processing by screen packs positioned at the end of an extruder barrel. However, in these bale-wrappers, the presence of both polyester and cellulosic (cotton and paper fibers) creates a unique problem. The cellulosic fibers degrade at temperatures required to melt-process polyesters, and at lower temperatures the cellulosic and polyester fibers cause plugging of the filter screens used in extruding the recycled polymer. Mechanical methods that have been attempted have failed to give good separations. In addition, washing with water, with or without detergent, is not a satisfactory approach. Furthermore, difficulties have been encountered in achieving a satisfactory process since the customers for reprocessable, reusable polyolefins have high specifications that are close to those for the original polyolefin material.